"It's good they can get the advanced payments, because otherwise they'd be on the street, but it can be hard having to then repay back the debt when they're still struggling to get food on the table."
Most beneficiaries who owed money to the ministry also had other debt, he said.
"Some have power-bill debt, others owe money through hire purchase.
"Truck shops are another biggy, especially at this time of year. The trucks go around to areas where the most vulnerable people live and sell them really overpriced goods on layby so it doesn't seem like much when you first get it.
"We tell people they're not worth it and give out 'do not knock on this door' signs but it's hard to say no, especially when you see things that would make nice presents for your kids.
"[Beneficiaries] want their kids to have a good Christmas, just like everyone else."
Nationally, a total of $627,780,079 was owed by beneficiaries at the end of the financial year.
Almost 60 per cent of 18- to 64-year-olds on a main benefit were in debt.
Main benefits include Jobseeker Support, Sole Parent Support, Supported Living Payment, Youth Payment, Young Parent Payment, Emergency Maintenance Allowance, Emergency Benefit and Jobseeker Support Student Hardship.
Ministry of Social Development spokesman Carl Crafar said the ministry worked hard to "protect the integrity of the system to ensure it remains fair to all New Zealanders".
Clients could owe money to the ministry because of overpayment, "recoverable assistance" or as a result of being prosecuted for fraud.
Recoverable assistance was a payment which helped people pay for something they needed urgently when they had no other way of paying for it, for example, school uniforms or rent arrears.
Most overpayments occurred because clients failed to inform Work and Income of a change in their circumstances, such as accommodation costs, Mr Crafar said.
"The ministry has a dedicated team of approximately 110 specialist fraud investigators throughout the country, and an intelligence unit that identifies emerging fraud risks and trends," he said.
"We work with other government agencies to identify and reduce the incidence of fraud and also investigate cases which arise through allegations from members of the public."
The ministry also aimed to minimise debt in the first place, he said.
Each year, the ministry administers $23 billion to provide income assistance and services to more than one million New Zealanders.
Avoiding debt at Christmas:
*Presents don't have to be big and expensive. Make your own colourful vouchers for jobs you can do, eg, gardening, babysitting, washing a car or housekeeping.
*Never pay full price for anything. Look for sales.
*Secret Santa family-style. Get every family member to put their name into a hat and the name pulled out receives a present from the whole family.
*Anything can go on a Christmas tree: fake flowers, small plastic animals, children's crafts, etc. They will look fab.
*Make Christmas lunch or dinner potluck. The library has fantastic cook books with budget recipes.
